
function Sine(){}

Sine._HALF_PI = Math.PI * 0.5;

Sine.easeIn  = function(t, b, c, d) 
{
	return -c * Math.cos(t/d * _HALF_PI) + c + b;
};

Sine.easeOut  = function(t, b, c, d) 
{
	return c * Math.sin(t/d * _HALF_PI) + b;
};

Sine.easeInOut  = function(t, b, c, d) 
{
	return -c*0.5 * (Math.cos(Math.PI*t/d) - 1) + b;
};